Section: Security Operation Adimnistration
Explanation/Reference:
A protection domain consists of the execution and memory space assigned to each process. The purpose of establishing a protection domain is to protect programs from all unauthorized modification or executional interference. The security perimeter is the boundary that separates the Trusted Computing Base (TCB) from the remainder of the system. Security labels are assigned to resources to denote a type of classification.
Abstraction is a way to protect resources in the fact that it involves viewing system components at a high level and ignoring its specific details, thus performing information hiding.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 5: Security Architecture and Models (page 193).

The keyword within the question is: preliminary
This means that you are starting your effort, you cannot audit if your infrastructure is not even in place.
Reference used for this question:
TIPTON, Hal, (ISC)2, Introduction to the CISSP Exam presentation.

Traffic padding is a countermeasure to traffic analysis.
Even if perfect cryptographic routines are used, the attacker can gain knowledge of the amount of traffic that was generated. The attacker might not know what Alice and Bob were talking about, but can know that they were talking and how much they talked. In certain circumstances this can be very bad. Consider for example when a military is organising a secret attack against another nation: it may suffice to alert the other nation for them to know merely that there is a lot of secret activity going on.
As another example, when encrypting Voice Over IP streams that use variable bit rate encoding, the number of bits per unit of time is not obscured, and this can be exploited to guess spoken phrases.
Padding messages is a way to make it harder to do traffic analysis. Normally, a number of random bits are appended to the end of the message with an indication at the end how much this random data is. The randomness should have a minimum value of 0, a maximum number of N and an even distribution between the two extremes. Note, that increasing 0 does not help, only increasing N helps, though that also means that a lower percentage of the channel will be used to transmit real data. Also note, that since the cryptographic routine is assumed to be uncrackable (otherwise the padding length itself is crackable), it does not help to put the padding anywhere else, e.g. at the beginning, in the middle, or in a sporadic manner.
The other answers are all techniques used to do Penetration Testing.
References:
KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, pages 233, 238.
and https://secure.wikimedia.org/wikipedia/en/wiki/Padding_%28cryptography%29#Traffic_anal ysis

Section: Access Control
Explanation/Reference:
MAC provides high security by regulating access based on the clearance of individual users and sensitivity labels for each object. Clearance levels and sensitivity levels cannot be modified by individual users -- for example, user Joe (SECRET clearance) cannot reclassify the "Presidential Doughnut Recipe" from "SECRET" to "CONFIDENTIAL" so that his friend Jane (CONFIDENTIAL clearance) can read it. The administrator is ultimately responsible for configuring this protection in accordance with security policy and directives from the Data Owner.
DAC is incorrect. In DAC, the data owner is responsible for controlling access to the object.
Access control matrix is incorrect. The access control matrix is a way of thinking about the access control needed by a population of subjects to a population of objects. This access control can be applied using rules, ACL's, capability tables, etc.
TACACS is incorrect. TACACS is a tool for performing user authentication.
References:
CBK, p. 187, Domain 2: Access Control.
AIO3, Chapter 4, Access Control.

Explanation/Reference:
An Exigent Circumstance is an unusual and time-sensitive circumstance that justifies conduct that might not be permissible or lawful in other circumstances.
For example, exigent circumstances may justify actions by law enforcement officers acting without a warrant such as a mortal danger to a young child. Examples of other exigent circumstances include protecting evidence or property from imminent destruction.
In US v Martinez, Justice Thomas of the United States Court of Appeal used these words:
"As a general rule, we define exigent circumstances as those circumstances that would cause a reasonable person to believe that entry was necessary to prevent physical harm to the officers or other persons, the destruction of relevant evidence, the escape of the suspect, or some other consequence improperly frustrating legitimate law enforcement efforts."
In Alvarado, Justice Blackburn of the Court of Appeals of Georgia referred to exigent circumstances in the context of a drug bust:
"The exigent circumstance doctrine provides that when probable cause has been established to believe that evidence will be removed or destroyed before a warrant can be obtained, a warrantless search and seizure can be justified. As many courts have noted, the need for the exigent circumstance doctrine is particularly compelling in narcotics cases, because contraband and records can be easily and quickly destroyed while a search is progressing. Police officers relying on this exception must demonstrate an objectively reasonable basis for deciding that immediate action is required." All of the other answers were only detractors made up and not legal terms.
Reference(s) used for this question:
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 313.
and
http://www.duhaime.org/LegalDictionary/E/ExigentCircumstances.aspx